JP2007154319A - Woven or knitted fabric suitable for artificial leather and method for producing artificial leather using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a woven or knitted fabric for providing artificial leather having a natural leather-like feeling, excellent mechanical performance represented by strength and elongation and an excellent feeling and aesthetic property. <P>SOLUTION: The woven or knitted fabric for artificial leather comprises an extra fine fiber-forming fiber which is composed of a water-soluble thermoplastic polyvinyl alcohol-based polymer (Fa) and a crystalline thermoplastic polymer (Fb) having ≥160°C melting point, has a single fiber fineness of extra fine fiber after the formation of extra fine fiber of 0.0003-0.9 decitex and satisfies K represented by formula K=α×√(D/1.10) (α is number of twists (T/M); D is a fiber fineness (dtex) composed of an extra fine fiber-forming fiber) of 43-8,660 and an interyarn void area Sj(μm<SP>2</SP>) of 50-45,000. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a woven or knitted fabric for artificial leather, and more particularly to a woven or knitted fabric for artificial leather having excellent high strength, high density and tear resistance.

  Conventionally, artificial leather has been mainly composed of ultrafine fibers and polymer elastic bodies in order to obtain flexibility and mechanical performance similar to natural leather, and various methods have been proposed for its specific production method. ing. However, the present situation is that a material that satisfies both a texture like natural leather and excellent mechanical performance has not yet been realized.

  A conventional method for producing a general artificial leather is roughly as follows. That is, for example, as a basic method for obtaining a flexible artificial leather, staples are formed from ultrafine fiber-generating fibers made of two types of polymers having different solubility, and are formed into a web using a card, a cross wrapper, a random weber, etc. After the fibers are entangled with each other by a punch or the like to form a non-woven fabric, an elastic polymer such as polyurethane is provided, and one component in the ultrafine fiber generating fiber is removed to make the fibers ultrafine and flexible artificial leather However, the artificial leather obtained by this method has a disadvantage that mechanical properties such as tensile strength and wear strength are inferior.

On the other hand, there is also a method for producing artificial leather by sandwiching a woven or knitted fabric between sheets made of sea-island structure fibers having a length of 10 mm or less, and applying high-speed fluid treatment thereto (for example, see Patent Document 1). However, this method has a certain effect for obtaining a high-density and short nap suede, but since the fiber length of the used fiber is short, the single fiber is easily pulled out and the wear strength may be reduced. .
In addition, a method of needle punching by overlapping a woven or knitted fabric between nonwoven webs or on one side is also known. However, in the conventional known technique, when a woven or knitted fabric is used, the yarn of the woven or knitted yarn is caught on the needle needle barb. Since the yarn constituting the knitted fabric is greatly damaged, the reinforcing effect is small and a sufficient expected effect cannot be obtained. In order to improve the product's fullness, appearance (especially in the case of napped formation) and quality, it is necessary to increase the degree of fiber entanglement. As a result, the damage of the constituent yarns is increased accordingly, the strength of the woven or knitted fabric is lowered, and the reinforcing effect is lowered. Furthermore, if the ends of the cut fibers from the woven or knitted fabric caused by damage to the woven or knitted fabric are exposed on the nonwoven fabric surface, thick knitted or knitted fabric fibers are present between the ultrafine fibers, which causes a significant deterioration in the appearance. There were drawbacks.

Japanese Patent Publication No. 60-29775

  The present invention solves the above problems, has a natural leather-like texture, is excellent in mechanical performance represented by tear resistance, is further excellent in softness and aesthetics, and further has a dense feeling similar to natural leather. The object is to provide a woven or knitted fabric suitable for artificial leather having a sense of fulfillment.

As a result of intensive studies conducted by the present inventors to achieve the above-mentioned problems, the present invention has been achieved.
That is, the present invention comprises a water-soluble thermoplastic polyvinyl alcohol polymer (Fa) and a crystalline thermoplastic polymer (Fb) having a melting point of 160 ° C. or higher, and the fineness of the ultrafine fiber after ultrafinening is 0.0003. It is comprised from the thread | yarn which is comprised from the ultrafine fiber generation | occurence | production fiber used as -0.9 dtex, and K represented by the following Formula is 43-8660, and the space | gap area Sj (micrometer < ² >) between this thread | yarn is 50- A woven or knitted fabric for artificial leather, characterized by being 45000.
K = α × √ (D / 1.10)
(However, α: Twist number (T / M) D: Yarn fineness (dtex) made of ultra fine fiber generating fiber)

  Further, the present invention is a method for producing artificial leather, in which the woven or knitted fabric for artificial leather and a fiber web are laminated and intertwined and integrated, and then subjected to ultrafine fiber treatment before or after applying the polymer elastic body.

The woven or knitted fabric of the present invention is suitable for artificial leather having excellent mechanical properties and natural leather-like texture.

The fibers for the woven or knitted fabric of the present invention include a polymer excellent in shrinkage characteristics (stress, rate) when dissolved in hot water, that is, a water-soluble thermoplastic polyvinyl alcohol polymer (Fa), and a crystal having a melting point of 160 ° C. or higher. It is necessary to be an ultrafine fiber-generating fiber with a heat-resistant thermoplastic polymer (Fb).
Next, the water-soluble thermoplastic polyvinyl alcohol polymer (Fa) (hereinafter sometimes abbreviated as PVA) that is preferably used in the woven or knitted fabric of the present invention will be described in detail. As PVA used for the fibers constituting the woven or knitted fabric of the present invention, those having a viscosity average degree of polymerization (hereinafter simply referred to as polymerization degree) of 200 to 500 are preferable, and a range of 230 to 470 is preferable, and 250 to 450 is particularly preferred. When the degree of polymerization is less than 200, the melt viscosity is too low and it is difficult to obtain a stable composite. When the degree of polymerization exceeds 500, the melt viscosity is too high, and it becomes difficult to discharge the polymer from the spinning nozzle. By using so-called low polymerization degree PVA having a polymerization degree of 500 or less, there is an advantage that the dissolution rate is increased when dissolving with hot water.

The polymerization degree (P) of PVA here is measured according to JIS-K6726. That is, after re-saponifying and purifying PVA, it is obtained by the following equation from the intrinsic viscosity [η] measured in water at 30 ° C.
P = ([η] 10 ³ /8.29) ^{(1 / 0.62)}
When the degree of polymerization is in the above range, the object of the present invention can be achieved more suitably.

  The saponification degree of the PVA of the present invention is 90 to 99.99 mol%. 93-99.98 mol% is preferable, 94-99.97 mol% is more preferable, 96-99.96 mol% is especially preferable. If the degree of saponification is less than 90 mol%, the thermal stability of PVA is poor, and not only satisfactory melt spinning cannot be carried out by thermal decomposition or gelation, but also biodegradability is reduced, and the copolymerization described later Depending on the type of monomer, the water-solubility of PVA is lowered, and the ultrafine fiber-generating fiber of the present invention may not be obtained. On the other hand, PVA having a saponification degree larger than 99.99 mol% cannot be produced stably.

  The PVA used in the present invention has biodegradability, and is decomposed into water and carbon dioxide when treated with activated sludge or buried in soil. The activated sludge method is preferable for the treatment of the PVA-containing waste liquid after dissolving the PVA. When the PVA aqueous solution is continuously treated with activated sludge, it is decomposed in 2 days to 1 month. Moreover, since PVA used for this invention has low combustion heat and the load with respect to an incinerator is small, you may incinerate PVA by drying the waste_water | drain which melt | dissolved PVA.

  160-230 degreeC is preferable, as for melting | fusing point (Tm) of PVA used for this invention, 170-227 degreeC is more preferable, 175-224 degreeC is especially preferable, and 180-220 degreeC is especially preferable. When the melting point is less than 160 ° C., the crystallinity of PVA is lowered and the fiber strength is lowered. On the other hand, when the melting point exceeds 230 ° C., the melt spinning temperature becomes high, and the spinning temperature and the decomposition temperature of PVA are close to each other, so that PVA fibers cannot be produced stably.

  The melting point of PVA is that when DSC is used, the temperature is raised to 250 ° C. in nitrogen at a heating rate of 10 ° C./min, cooled to room temperature, and then heated again to 250 ° C. at a heating rate of 10 ° C./min. It means the temperature at the peak top of the endothermic peak indicating the melting point of PVA.

  PVA can be obtained by saponifying a polymer mainly composed of vinyl ester units. Vinyl compound monomers for forming vinyl ester units include vinyl formate, vinyl acetate, vinyl propionate, vinyl valenate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate and Examples include vinyl versatate, and among these, vinyl acetate is preferable from the viewpoint of easily obtaining PVA.

  The PVA used in the present invention may be a homopolymer or a modified PVA into which copolymer units are introduced. However, from the viewpoint of melt spinnability, water solubility, and fiber properties, copolymer units are introduced. It is preferable to use modified PVA. The types of comonomer include ethylene, propylene, 1-butene, and isobutene having 4 or less α-olefins, methyl vinyl ether, and ethyl vinyl ether from the viewpoints of copolymerizability, melt spinnability, and water solubility of the fiber. , Vinyl ethers such as n-propyl vinyl ether, i-propyl vinyl ether and n-butyl vinyl ether are preferred. The unit derived from α-olefins having 4 or less carbon atoms and / or vinyl ethers is preferably present in PVA in an amount of 1 to 20 mol%, more preferably 4 to 15 mol%, and 6 to 13 mol%. Is particularly preferred. Further, when the α-olefin is ethylene, the fiber physical properties are high, and therefore, this is a case where a modified PVA into which ethylene units are introduced in an amount of 4 to 15 mol%, more preferably 6 to 13 mol% is used. .

  Examples of the PVA used in the present invention include known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Among them, a bulk polymerization method or a solution polymerization method in which polymerization is performed without solvent or in a solvent such as alcohol is usually employed. Examples of alcohol used as a solvent during solution polymerization include lower alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol. Examples of the initiator used for copolymerization include a, a｀-azobisisobutyronitrile, 2,2｀-azobis (2,4-dimethyl-valeronitrile), benzoyl peroxide, n-propyl peroxycarbonate, and the like. And known initiators such as azo initiators and peroxide initiators. Although there is no restriction | limiting in particular about superposition | polymerization temperature, The range of 0 to 150 degreeC is suitable.

The polymer constituting the crystalline thermoplastic polymer (Fb) having a melting point of 160 ° C. or higher of the present invention is not particularly limited, but polyethylene terephthalate (hereinafter sometimes abbreviated as PET), polytrimethylene terephthalate, poly Butylene terephthalate (hereinafter sometimes abbreviated as PBT), polyesters such as polyester elastomer, nylons 6, nylon 66, nylon 610, polyamides such as aromatic polyamide, polyamide elastomer, polyurethanes, polyolefins, acrylonitriles A polymer having a fiber-forming ability such as is suitable. Among these, PET, PBT, nylon 6, nylon 66 and the like are particularly desirable from the viewpoint of the texture and practical performance of the processed product. And it is important that these polymers have a melting point of 160 ° C. or higher. When the temperature is lower than 160 ° C., the form stability is inferior, and there is a problem in terms of practicality.
The melting point is the value when DSC is used and the temperature is raised to 250 ° C. in nitrogen at a heating rate of 10 ° C./min, cooled to room temperature, and then heated again to 250 ° C. at a heating rate of 10 ° C./min. It means the temperature at the peak top of the endothermic peak indicating the melting point of the polymer.

  (Fa) of the ultrafine fiber generating fiber constituting the woven or knitted fabric of the present invention is extracted and removed by a known method, and an ultrafine fiber comprising a crystalline thermoplastic polymer (Fb) having a melting point of 160 ° C. or higher after ultrafine fiber formation. As for the single fineness, 0.0003 to 0.9 dtex is adopted in order to enhance the performance as an artificial leather, that is, flexibility, touch feeling, appearance quality, strength characteristics and the like. Preferably it is 0.003-0.5 dtex, More preferably, it is the range of 0.007-0.3 dtex.

Moreover, it is necessary to be comprised from the thread | yarn satisfy | filling K represented by the following Formula 43-8660. K = α × √ (D / 1.10)
(However, α: Twist number (T / M) D: Yarn fineness (dtex) made of ultra fine fiber generating fiber
When K exceeds 8660, the shrinkage force of the fiber decreases as the number of twists increases, and a dense feeling as an artificial leather cannot be obtained, and the integration with the nonwoven fabric by needle punch is insufficient, resulting in poor quality. . When K is less than 43, the passing through the weaving process is deteriorated, and the yarn is cut or damaged by the needle at the time of needle punching, so that the strength of the fabric structure is significantly reduced. The lower limit is preferably 100 or more, and more preferably 200 or more. The upper limit is preferably 8000 or less, and more preferably 7500 or less.
In order to make K within the above range, there is no particular limitation as long as the number of twists and the fineness of the fine fiber-generating fiber are appropriately adjusted.

Furthermore, it is important that the void area between the yarns of the woven or knitted fabric is in the range of 50 to 45000 (μm ² ). When the gap is less than 50 μm ² , when needle punching, a thread or single thread (single fiber) is caught on the barb of the needle, and the thread is cut or damaged. Furthermore, the structure of the woven or knitted fabric is destroyed, and the strength of the woven or knitted fabric is remarkably lowered with an increase in the number of punches, and the overall fabric structure is significantly lowered. On the other hand, when the gap is larger than 45000 μm ^{2, the} texture and bagging properties are insufficient. The lower limit is preferably 100 [mu] m ² or more, more preferably 200 [mu] m ² or more, 3000 .mu.m ² or more are particularly preferred. The upper limit is preferably 40000Myuemu ² or less, more preferably 20000Myuemu ² or less, 10000 ² below are particularly preferred.
The gap area between the yarns is the gap part surrounded by the yarn using a scanning electron microscope when the woven or knitted fabric is viewed from above (for example, in the case of a plain fabric, the part surrounded by warp and weft yarns) ) Is selected, and the area is measured and averaged.

  The cross-sectional shape of such an ultrafine fiber-generating fiber is a sea-island type in which PVA is a sea component and a crystalline thermoplastic polymer is an island component, and PVA and a crystalline thermoplastic polymer are bonded together in a multi-layered state. And a multi-layered type. The reason why a high-density fabric is obtained by combining with PVA is not clear at the present time, but it is presumed that the high density fabric is reached due to the strong shrinkage stress generated when the PVA is dissolved. This densification tends to be expressed more strongly as the ratio of the PVA component in the fiber is higher. As a mass ratio of PVA in the woven or knitted fabric before PVA dissolution and removal, 5 to 70 mass% is preferable. More preferably, it is 10-60 mass%, Most preferably, it is 15-50 mass%.

  As described above, the fiber constituting the yarn of the woven or knitted fabric is an ultrafine fiber generating fiber, but the single fineness of the ultrafine fiber generating fiber is preferably in the range of 1 to 5 dtex. Moreover, it is preferable from the point of fiberization process property that such a fiber has a form of a filament (long fiber), and therefore, a multifilament yarn is preferable as a yarn constituting the woven or knitted fabric. The thickness of the multifilament yarn is preferably in the range of 50 to 150 dtex.

The basis weight of the woven or knitted fabric can be appropriately set according to the purpose, but is desirably in the range of ^{20 to} 200 g / m ² after the ultrafine treatment, and most preferably in the range of 30 to 150 g / m ² . When the basis weight is less than 20 g / m ² , the form as a woven or knitted fabric becomes very loose, and the fabric lacks stability such as misalignment. On the other hand, when the basis weight exceeds 200 g / m ² , the knitted and knitted fabric structure becomes dense, the penetration of the nonwoven fabric fibers is insufficient, and the nonwoven fabric does not progress in high entanglement, making it difficult to make a structure that is inseparably integrated. As for the types of woven and knitted fabrics, weft knitting represented by warp knitting and tricot knitting, lace knitting and various knittings based on these knitting methods, or plain weaving, twill weaving, satin weaving and weaving them Various kinds of woven fabrics can be mentioned. From the viewpoint of surface flatness of artificial leather, a relatively plain woven structure, for example, a plain woven structure, a 2/2 weft weave structure (vertical two weft weft structure), a twill weave structure, etc. In particular, a plain weave structure is most preferable in consideration of cost.

  The warp and / or weft arrangements are Z / Z arrangement (arrangement of only Z-twisted yarn), S / S arrangement (arrangement of only S-twisted yarn), S / Z alternate arrangement (S-twisted yarn and Z The twisted yarns may be either one or two alternates, or even three or more alternates), but one alternate S / Z arrangement reduces the fabric torque. As a result, the woven fabric is flat and free of fabric curl, which is more preferable. Weaving looms include fluid jet looms such as air jet looms and water jet looms, as well as rapier rooms, gripper rooms, fly shuttle looms, etc. A fluid jet loom such as an air jet loom or a water jet loom, which is capable of low tension weft insertion and is gentle to the weft, is preferable, and it is particularly preferable to use an air jet loom. preferable.

Artificial leather is produced by laminating a woven and knitted fabric for artificial leather and a fiber web obtained as described above, entangled and integrated, and then performing ultrafine fiberization treatment before or after applying the polymer elastic body, These individual production methods are not particularly limited and can be produced by known methods.
For example, the fiber web can be obtained by a known method for producing artificial leather, but has the same water-soluble thermoplastic polyvinyl alcohol polymer (Fa) as the woven or knitted fabric for artificial leather and a melting point of 160 ° C. or higher. The crystalline thermoplastic polymer (Fb) is preferably used from the standpoint that an artificial leather with a sense of unity and stable mechanical properties can be obtained by using an ultrafine fiber-generating fiber having the same component as the crystalline thermoplastic polymer (Fb). A known method is also particularly used for the lamination and entanglement integration of the fiber web and the woven or knitted fabric for artificial leather, and the entanglement treatment by needle punch is preferable. And it is preferable in terms of densification and smoothing of the surface to shrink the fiber entangled body after the entanglement treatment by dry heat treatment by 30% or more in terms of area. Next, a polymer elastic body is imparted to the obtained fiber entangled body, and the polymer elastic body used is a known one used for artificial leather, and particularly polyurethane has both a feeling and mechanical properties. Are preferably used. Before or after applying the polymer elastic body, it is necessary to make the ultrafine fiber generating fiber into ultrafine fibers. However, it is possible to use a known method for making ultrafine fibers, and as described above, the fiber web and artificial leather If the constituent components of the fibers constituting the woven or knitted fabric are the same, it is preferable in that the ultrafine fiber treatment can be completed at once.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to an Example. In addition, evaluation in an Example and a comparative example was measured with the following method.

[Evaluation of fiber processability]
Depending on how many times the fiber was cut when spinning 100 kg of fiber, the evaluation was as follows.
○: Within 3 times / 100kg
Δ: 4-7 times / 100 kg
×: 8 times / 100kg
[Texture and appearance quality of artificial leather (aesthetics)]
As a result of the evaluation by the following evaluation methods by 10 persons involved in the development of artificial leather, the results of occupying the most evaluations are shown.
◎: Appearance is very good with a texture similar to that of very soft natural leather. ○: Appearance is excellent with a texture similar to that of soft natural leather. Is very inferior [Strength of artificial leather]
Tensile strength and elongation: Measured according to JIS-L1079 5, 12, 1.

[Production of water-soluble thermoplastic raw polyvinyl alcohol]
A 100-liter pressurized reactor equipped with a stirrer, nitrogen inlet, ethylene inlet and initiator addition port was charged with 29.0 kg of vinyl acetate and 31.0 kg of methanol, heated to 60 ° C., and then bubbled for 30 minutes with nitrogen bubbling. Was replaced with nitrogen. Next, ethylene was introduced and charged so that the reactor pressure was 5.9 kg / cm ² . Prepare a 2.8 g / L solution of 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) dissolved in methanol as an initiator, and perform nitrogen replacement by bubbling with nitrogen gas. did. After adjusting the temperature inside the polymerization tank to 60 ° C., 170 ml of the initiator solution was injected to start polymerization. During the polymerization, ethylene was introduced to maintain the reactor pressure at 5.9 kg / cm, the polymerization temperature at 60 ° C., and AMV was continuously added at 610 ml / hr using the above initiator solution. . After 10 hours, when the polymerization rate reached 70%, the polymerization was stopped by cooling. After the reaction vessel was opened to remove ethylene, nitrogen gas was bubbled to completely remove ethylene. Next, unreacted vinyl acetate monomer was removed under reduced pressure to obtain a methanol solution of polyvinyl acetate. 46.5 g (polyvinyl acetate in acetic acid of polyvinyl acetate) was added to 200 g of polyvinyl acetate in methanol (100 g of polyvinyl acetate in the solution) adjusted to a concentration of 50% by adding methanol to the obtained polyvinyl acetate solution. Saponification was carried out by adding an alkaline solution (NaOH in 10% methanol) having a molar ratio (MR) of 0.10 to the vinyl unit. About 2 minutes after the addition of the alkali, the gelled system was pulverized with a pulverizer and allowed to stand at 60 ° C. for 1 hour to allow saponification to proceed, and then 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the end of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was left to wash at room temperature for 3 hours. After repeating the above washing operation three times, the PVA obtained by centrifugal drainage was left in a dryer at 70 ° C. for 2 days to obtain dry PVA.

The saponification degree of the obtained ethylene-modified PVA was 98.4 mol%. Further, after the modified PVA was incinerated, the content of sodium measured by an atomic absorption photometer using a material dissolved in an acid was 0.03 parts by mass with respect to 100 parts by mass of the modified PVA. In addition, after removing the unreacted vinyl acetate monomer after the polymerization, a methanol solution of polyvinyl acetate obtained by precipitation in n-hexane and reprecipitation purification by dissolving with acetone was performed three times, followed by drying at 80 ° C. under reduced pressure for 3 days. To obtain purified polyvinyl acetate. When the polyvinyl acetate was dissolved in d6-DMSO and measured at 80 ° C. using 500 MHz proton NMR (JEOL GX-500), the ethylene content was 10 mol%. After saponifying the above methanol solution of polyvinyl acetate at an alkali molar ratio of 0.5, the pulverized product was allowed to stand at 60 ° C. for 5 hours to allow saponification to proceed, followed by methanol soxhlet for 3 days, and then at 80 ° C. And purified under reduced pressure for 3 days to obtain purified ethylene-modified PVA. It was 330 when the average degree of polymerization of this PVA was measured according to JIS K6726 of the usual method. The amount of 1,2-glycol bonds and the content of hydroxyl groups in the 3-linked hydroxyl group of the purified PVA were determined as described above from measurement with a 5000 MHz proton NMR (JEOL GX-500) apparatus, and found to be 1.50 mol% and 83%, respectively. Met. Further, a cast film having a thickness of 10 microns was prepared by preparing a 5% aqueous solution of the purified modified PVA. After the film was dried under reduced pressure at 80 ° C. for 1 day, the melting point of PVA was measured by the above-mentioned method using DSC (Mettler, TA3000), and found to be 206 ° C.
Further, in the above PVA production method, various PVAs were produced by changing the copolymerization component, the copolymerization ratio, the polymerization degree, the saponification degree, and the like. The results are shown in Table 1.

[Manufacture of woven and knitted fabric]
Polyethylene terephthalate (hereinafter referred to as IPA modified) containing 10 mol% of isophthalic acid having an intrinsic viscosity of 0.65 (measured at 30 ° C. in an equal weight mixed solution of phenol / tetrachloroethane) using the PVA as a sea component. (May be called PET.) (Melting point: 234 ° C.) Using a die for melt compound spinning (0.25φ, 24 holes) in which the tip is an island component and the island component is 36 islands, and discharged from the die at 250 ° C. Spinning was performed (sea-island ratio = 4: 6 (mass ratio)). The spun fiber was drawn by a roller plate method under normal conditions to obtain a sea-island type composite multifilament fiber having a yarn fineness of 84 dtex-24 filaments. The spinning property, continuous running property, and stretchability were good, and there were no problems. This sea-island type ultrafine fiber generating fiber was twisted to 500 T / M to produce a plain fabric. (Density is designed to be the values shown in Table 2)

[Manufacture of fiber web]
Polyethylene terephthalate containing 10 mol% isophthalic acid (melting point: 234 ° C.) having an intrinsic viscosity of 0.65 (measured at 30 ° C. in an equimolar mixed solution of phenol / tetrachloroethane) using the PVA as a sea component A melt compound spinning die (0.25φ, 550 holes) in which the chip component is an island component and the island component is 37 islands was discharged from the die at a temperature of 250 ° C. for spinning. The spun fiber was drawn by a roller plate method under normal conditions. The spinning property, continuous running property, and stretchability were good, and there were no problems. This sea-island type ultrafine fiber generating fiber was crimped with a crimping machine and cut into 51 mm to be stapled. A fiber web having a basis weight of 500 g / m ² was produced from this staple by a cross wrap method.

The fiber web and plain woven fabric are laminated, then needle punched under the condition of 1500 punch / cm ² , and subjected to a dry heat treatment at 150 ° C. to shrink the fiber entangled body by 30% in terms of area (therefore, the area after the shrink treatment is The area ratio before shrinkage treatment was 70%), and a fiber entangled body having a smooth surface was obtained. The fiber entangled body was impregnated with a 13% dimethylformaldehyde solution of polyether polyurethane, immersed in a dimethylformaldehyde / water mixture, and solidified by immersion, followed by sea components and sheaths in hot water (90 ° C.). The component PVA polymer was eluted and removed to obtain artificial leather. When the PVA polymer was extracted and removed, the sheet contracted, and the area ratio decreased to 80% before the extraction process. The mass ratio of the elastic polymer in the artificial leather was 21%, and the thickness of the artificial leather was 0.8 mm. By buffing the nonwoven fabric side surface of the obtained artificial leather with sandpaper, a suede-like artificial leather having fine napping on the surface was obtained. Furthermore, physical properties of the obtained artificial leather are shown in Table 3.

[Examples 2-3]
Example of production of multifilament yarn for woven and knitted fabric, except that the number of islands of sea-island type ultrafine fiber generating fiber was changed to 600 islands, or the yarn fineness was changed to 167 dtex to change the fiber thickness after removing sea components. 1 was carried out in the same manner.

[Examples 4 to 5]
In the production of the woven or knitted fabric, the same procedure as in Example 1 was performed except that the number of twists of the multifilament yarn was changed to the number of twists shown in Table 2.

[Examples 6 to 7]
In the production of the woven or knitted fabric, the same procedure as in Example 1 was performed, except that the density was adjusted so that the number of twists of the multifilament yarn was a void area as shown in Table 2.

[Examples 8 to 9]
In the production of woven and knitted fabrics, as shown in Table 2, the island component of the sea-island type ultrafine fiber generating fiber was changed to Ny6 and PLLA, and in the production of the fiber web, the island component was changed to Ny6 (nylon 6), PLLA (poly The same method as in Example 1 was performed except that the lactic acid was changed.

[Examples 10 to 11]
In the production of the multifilament yarn for woven and knitted fabric, the same procedure as in Example 1 was performed except that the sea components of the sea-island type ultrafine fiber generating fiber were changed as shown in Table 2.

[Comparative Example 1]
In the production of the multifilament yarn for woven and knitted fabric, the same method as in Example 1 was used except that the number of islands of the sea-island type ultrafine fiber generating fiber was changed to 2 and the thickness of the fiber after removal of the sea component was changed. Carried out.

[Comparative Examples 2-3]
In the production of the woven or knitted fabric, the same procedure as in Example 1 was performed except that the number of twists of the multifilament yarn was changed to the number of twists shown in Table 2.

[Comparative Examples 4 to 5]
In the production of the woven or knitted fabric, the same procedure as in Example 1 was performed, except that the density was adjusted so that the number of twists of the multifilament yarn was a void area as shown in Table 2.

Claims (2)

It consists of a water-soluble thermoplastic polyvinyl alcohol polymer (Fa) and a crystalline thermoplastic polymer (Fb) having a melting point of 160 ° C. or higher, and the fineness of the ultrafine fiber after ultrafinening is 0.0003 to 0.9 dtex It is comprised from the thread | yarn which is comprised from the ultrafine fiber generation type | formula which becomes, and K represented by the following Formula satisfies 43-8660, and the space | gap area Sj (micrometer < ² >) between this thread | yarn is 50-45000, It is characterized by the above-mentioned. Weaving and knitting for artificial leather.
K = α × √ (D / 1.10)
(However, α: Twist number (T / M) D: Yarn fineness (dtex) made of ultra fine fiber generating fiber) A method for producing artificial leather, comprising: laminating the woven or knitted fabric for artificial leather and a fiber web according to claim 1, performing entanglement integration, and performing ultrafine fiber treatment before or after applying a polymer elastic body.